Discontinuous helical auger contained within a heated vessel filled with sawdust for the purpose of high efficiency breakdown of toilet and other organic wastes

ABSTRACT

The invention consists of a discontinuous helical auger contained within a heated vessel filled with sawdust. The auger enables thorough turning of sawdust enclosed within a heated vessel enabling function of the assembly as a waterless biotoilet. Control of auger rotation works to maximize the biodegradation of human toilet waste through physical breakdown of organic matter, through stimulation of evaporation of the aqueous fraction, and through supporting a benign microflora to effect biodegradation. This discontinuous helical auger enables maintenance of a flat horizontal upper planar surface of the sawdust mass while maximizing aeration of the sawdust mass. The angle of the helical blade and discontinuities therein work to draw the organic matter very gradually toward the opposite end of the biotoilet from the toilet hole, maximizing dewatering and aerobic breakdown.

REFERENCES CITED

U.S. PATENT DOCUMENTS 7,103,926 Rasberry 6,260,216 Lejgren 5,345,620 Sundberg

BACKGROUND

Waterless toilets effecting the safe and complete treatment of human toilet wastes amongst other forms of organic waste have been around ever since the digging of the first outhouse. Various steps can be seen in the evolution of waterless toilets, including compartmentalization of wastes (digging a hole), elaborating that hole to a tank (septic tanks), bringing that tank above ground (above ground in-vessel toilets), ending in several evolutionary branches—those toilets that burn the waste (incinerating toilets), those toilets that send the waste elsewhere (flush-to-sewer or flush-to-collection toilets), and those toilets that break down the waste amongst a high-lignin organic matter matrix (composting toilets).

In U.S. Pat. No. 7,103,926 by Rasberry, Rasberry's simple patented design of the portable latrine brought the vessel out of the ground. Though seemingly simple, the removal of the interface between the vessel for human wastes and the soil and groundwater allowed for control of the flow of pathogens vectored by urine into the environment.

Lejgren, in the U.S. Pat. No. 6,260,216, captures the idea of an above ground receiving vessel for human waste, and adds a sliding grid for winnowing down of the introduced solids. This element of motion has been emulated in a series of composting toilets, mostly unpatented. All of these planar methods of agitation are prone to failure through jamming; more importantly, they do not allow the conservation of a relatively inert abrasive and absorptive medium like sawdust to be used in the technology.

These two ideas of the above ground vessel and the agitating element were elsewhere elaborated in U.S. Pat. No. 5,345,620 by Sundberg, who changes the vessel into a rotating drum, providing a way to conserve the inert organic matter. Three failings with this design are the tremendous amount of torque necessary to rotate a barrel full of wet organic matter, incomplete aeration of the middle of the mass leading to odiferous anaerobic breakdown, and the inability to apply uniform heat across the surface area of the vessel exterior.

Naturally, continued evolution and improvement in the moving parts of a waterless toilet is required to maximize organic matter breakdown, liquid fraction evaporation, and pathogen kill, leading to this patent application.

The above-mentioned, and many other, toilet patents over a century have led to the evolution of the present utility design for which a patent is requested. That is, a composting toilet box containing an above-ground vessel, to the exterior of which heat is applied, containing an independently rotating discontinuous helical auger, allowing for the conservation of the relatively inert sawdust abrasive medium, or even an inorganic matrix such as porous plastic beads. All these features serve to optimize the complete breakdown of introduced organic matter through physical abrasion, dewatering, evaporation of the water content, support of a benign biodegrading aerobic microflora whose provenance is the sawdust and whose function is to biodegrader the organic waste, and finally thermal kill of animal pathogens. Further components include electronics control of these various elements, and an insulated layer between the composting vessel and the external box.

BRIEF SUMMARY OF THE INVENTION

Broadly speaking, all composting toilets encourage the breakdown of organic wastes, principally human faeces. Some drain off the liquid portion, some attempt to evaporate it with a dryer mechanism. Using the remarkable properties of sawdust, including high water holding capacity, immense surface area, resistance to complete saturation, and physical abrasive properties, the discontinuous helical auger can be used to effect complete physical breakdown, evaporation of water, and kill of animal pathogens if maintained in the correct heat environment. The discontinuous helical auger acts to turn the mass of sawdust over such that the upper horizontal planar surface of the sawdust mass is not disturbed, obviating the mounding of sawdust to either end or the middle. The sawdust and auger are contained within a heated vessel that allows for ingress of toilet and other organic wastes (e.g. food waste, diseased dead birds) such that that matter is drawn extremely slowly first toward the middle and finally to the other end, where all that remain are inorganic elements and other traces. An air fan removes vapor-laden air and vents it to the outside. Odor is minimized owing to the shape of the auger not allowing for anaerobic pockets of sawdust leading to anaerobic reactions leading to smell. Physical breakdown is achieved through the abrasion of the sawdust powered by the auger blade, and simply the auger blade itself powered under very high gear reduction.

In the drawings, which form part of this specification:

FIG. 1, (see Fig1augerinbiotoilet.tif), is a semi-diagrammatical cross-sectional view of the horizontal placement of the auger beneath the toilet hole, with the sawdust mass, inside the heated vessel, within a supporting superstructure to form the entire toilet.

FIG. 2, (see Fig2augeritself.tif), shows an elevated oblique transverse view of the auger, displaying discontinuities and sweepers.

FIG. 3, (see Fig3augercross-section.tif), is a cross-sectional view of the auger.

DETAILED DESCRIPTION OF THE INVENTION

In the idealized cross-sectional side view of the waterless Biodegrader biotoilet, a person sits upon a toilet seat 6 atop a toilet hole 5 leading to a stainless steel vessel 3 suspended by brackets 32 to hold a sawdust matrix mass A heated by electric heaters 31. A transverse axle 10 supports spokes 13 with optional spoke supports 12, 12A that in turn support the discontinuous helical blade 11, 11A that turns under the power of a geared engine box 9. The toilet room floor 2 can be a floating floor if the height of the toilet unit is too high, and the entire box airspace A2 above the sawdust mass is actively vented out a vent pipe 7. Spent sawdust is removed through an access hatch 8 set into the box 4 when refreshing of sawdust required. Sweeper flanges such as 15 work to scrape any solids away from the ends of the machine, avoiding anaerobic pockets.

FIG. 2 illustrates the invention itself, the discontinuous helical auger. Welded to the stainless steel horizontal axis 10 can be seen horizontal stainless steel supports 12, 12A, welded to stainless steel spokes 11, 11A which in turn are welded to the discontinuous helical steel blade portion 11, 11A. The gaps in the helical blade are indicated in S and S1, and the terminal ends of the auger are welded to special stainless steel arms 15, 15A that incorporate sweeper scrapers to ensure no accumulation of matter occurs on either terminal end of the vessel. A and A1 refer to the lower and upper halves of the sawdust mass respectively.

FIG. 3 exhibits the auger in cross-section showing the same vent pipe 7 at the top, venting the airspace A2 above the sawdust. The discontinuous nature of the blade is approximated by 11A, with protruding stubs 14A affording some bite into the organic matter. Supports 10 prevent breakdown of the spoke-supported discontinuous helical blade. An access hatch 8 provides removal access for spent sawdust; however, that spent sawdust will have no enteric pathogens nor virtually no organic matter other than the sawdust at this point since all matter will have traveled down the long path to this distal, removal end.

Modifications in the attachment of spokes, detection devices within the auger, the use of two augers in tandem, and the length and diameter of the auger will simply change the turning potential of the auger, so long as the strength and dimensions of the stainless steel remains in relative proportion. Materials other than stainless steel such as carbon fibre can be envisioned but would require extensive testing for tensile strength and long-term resistance to chemical breakdown. Higher quality welding is particularly necessary in the auger itself.

Although the most widespread use of this biodegrader machine incorporating the helical auger would be as a toilet, the same technology can also be used to sanitarily process food waste, manure from other animals, and finally diseased dead animals the pathogens in which must be deactivated prior to disposal. 

1: The discontinuous helical auger is a novel architecture that optimizes safe and environmentally responsible treatment of organic matter waste within an in-vessel organic matter biodegrader machine, that is to say, within an enclosed vessel that contains mechanical equipment and a relatively inert physical matrix amendment that together act as a basis for biodegradation of organic matter and evaporation of any water released. 2: The discontinuous helical nature of the auger blade allows for virtually complete turning of the entire matrix material (e.g. sawdust) mass while preventing mounding of sawdust within the vessel. In effect, the flow of this matrix material is such that progress is imperceptible of introduced organic matter from the toilet hole end to the distal end of the in-vessel composter where spent sawdust is periodically removed. 3: Attaching the discontinuous helical blade to the rotating axis of the auger with spokes allows for minimization of the weight of the auger as opposed to a solid surface auger. This allows for a great volume of sawdust to be turned over and aerated with relatively small motors, saving electricity. 4: The discontinuous helical nature of the auger with its terminal sweepers enable virtually entire turnover of the matrix material mass and any organic matter included within this matrix. This means that clumping of sawdust and introduced solid and liquid matter is avoided both on the sides and the ends of the drum, and on the auger itself. This prevents anaerobic pockets leading to anaerobic fermentation reactions giving rise to unpleasant odor. Accordingly, the architecture of the auger directly reduces malodor emanating from the in-vessel biodegrader toilet. 6: The self-cleaning nature of the discontinuous helical auger allows for placement of temperature, moisture, and other electrical sensors within the auger itself. A principal challenge for many in-vessel systems is keeping the electrical sensors clean. 7: The complete turnover capacity of the discontinuous helical auger allows for the distribution of heat applied, e.g. to the walls of the containing vessel. With thermostatic control, this allows for the uniformity of temperature across the entire body of the mass. This uniform temperature control enabled by the auger allows for the selection of specific microflora, enabling the biodegrader biotoilet to both inactivate animal pathogens originally present in the introduced organic matter such as Escherium coli in human faeces, while establishing optimum growth conditions for beneficial, benign microflora that biodegrade organic matter aerobically. 